When people talk about Bitcoin price, they usually refer to its price expressed in dollars. I really don't understand why...
US Dollar is going down in price, US economy is collapsing. There are many other countries which has more Bitcoin users, like Russia, China, Japan, Philippines and the whole Eurozone. Even ICOs are forbidden in the USA. It's not a so Bitcoin-friendly country, its national currency is not so strong. So why price Bitcoin in $?
There could be many other more appropriate currencies like EUR, CNY or RUB...
Compared to other fiat currency, by far on record, US Dollars have been the most stable currency and globally regarded fiat currency. Since then, financial analysts have used Dollars to value a lot of things including crude oil. It's easy to value bitcoins when gauged to dollars.
Yes, it easy to track when both most popular currency have been value for its reference. Dollar is the most popular real currency and Bitcoin too in crypto currency then the fact that on this day still there are few establishment accept bitcoin as medium of exchange therefore every individual must convert it into real money regardless of what currency.